Benchmark on deterministic 3-D MOX fuel assembly transport calculations without spatial homogenization

Within the framework of the OECD/NEA Expert Group on 3-D Radiation Transport Benchmarks, an international benchmark exercise for testing the ability of modern deterministic transport methods and codes to treat reactor problems without spatial homogenization was proposed in March 2001. That benchmark was completed in 2003 and the OECD report is available. As a follow-up to that benchmark, an extension of the 3-D calculations was proposed in May 2003 to provide a more challenging test of present day three-dimensional methods' ability to handle spatial homogeneities. Control rods were introduced, adding to the heterogeneity of the problems. The reactor core size was decreased to reduce the computational burden on all participants. Fourteen solutions were submitted for the new benchmark by 12 participants. All of the participant solutions were compared to a reference multigroup Monte Carlo solution. The analysis of results shows modern deterministic transport codes and methods can calculate the flux distribution reasonably well without relying upon spatial homogenization techniques, provided the domain size is small enough that the problem can be performed on available computing equipment.